Once shrimp are caught and removed from water they must be deheaded within a relatively short period of time or frozen whole to delay the decaying action of bacteria within the head. Heretofore, shrimp have been deheaded by manually pulling the head from the body of the shrimp. This process however is labor intensive and time consuming.
Automated apparatuses have been designed for deheading shrimp as shown in U.S. Pat. No. 4,692,965. These apparatuses dehead shrimp by bending the shrimp quickly around an edge as they move from a vertical tube of slow moving fluid to a horizontal tube of fast moving fluid. However, because the orientation of the shrimp is not consistent, as well as other variables involving the force required to dehead shrimp, these apparatuses do not always dehead the shrimp. Furthermore, the separated heads and bodies of the shrimp are conveyed within the same stream of fluid, thus requiring further separation of these portions.
Shrimp deheading apparatuses have also been designed which have a blade which severs the head from the body, as shown in U.S. Pat. No. 4,016,625. However, due to differences in the size of shrimp these apparatuses sometimes sever within the head thus causing portions of the head to remain attached to the body. Conversely, the shrimp are sometimes severed within the body thus causing a portion of the body meat of the shrimp to remain attached to the head and therefore wasted. Also, even when a shrimp is severed properly between the head and body, a portion of the body meat which extends into the head is severed from the body and discarded with the head, thereby causing that portion to be wasted. These situations obviously cause inefficiencies and increases in the overall cost of processed shrimp.
Shrimp deheading apparatuses have also designed which remove the head by "pinching" it from the body, as shown in U.S. Pat. No. 4,941,233. A problem however occurred with the proper positioning of the shrimp immediately prior to the pinching action. Oftentimes, differences in the natural curvature of shrimp causes shrimp to be oriented at different angles as they are pinched between a deheading finger and a deheading block. It has been found that a consistent orientation of the shrimp is an important factor in properly removing the head and optimizing the recovery of shrimp meat within the head.
Accordingly, it is seen that a need has long existed for methods and apparatuses for deheading shrimp in a commercially efficient and effective manner. It is to the provision of such methods and apparatuses therefore that the present invention is primarily directed.